1. Field of the Invention
The present invention relates to novel tetracoordinated tin compounds and to the use of such novel compounds as "latent" catalysts.
2. Description of the Prior Art
Numerous tin compounds have to date been proposed to this art as catalysts, in particular for:
(a) polyurethane synthesis: tin chelates (U.S. Pat. No. 3,055,845) and the products of reaction between a tin (IV) carboxylate and a sulfonyl isocyanate (DE-A-3,326,566 and EP-A-232,541), for example; PA1 (b) the crosslinking of silicone polymers by a polycondensation reaction: dialkyltin dicarboxylates (Noll, Chemistry and Technology of Silicones, page 337, 2nd Edition, Academic Press (1968)), and dialkyltin bischelates (EP-A-147,323 and U.S. Pat. No. 4,517,337), for example. PA1 R: butyl, octyl and phenyl; PA1 R.sub.1 : H; PA1 R.sub.2 : H, methyl and cyano; PA1 R.sub.3 : H, methyl, undecanoyl, 2-ethylpentyl, nonyl and ethoxy; and PA1 a=1.